These are the most recent NASA Hubble Space Telescope views of an unusual phenomenon in space called a light echo. Light from a star that erupted nearly five years ago continues propagating outward through a cloud of dust surrounding the star. The light reflects or "echoes" off the dust and then travels to Earth.
Because of the extra distance the scattered light travels, it reaches the Earth long after the light from the stellar outburst itself. Therefore, a light echo is an analog of a sound echo produced, for example, when sound from an Alpine yodeler echoes off of the surrounding mountainsides.
The echo comes from the unusual variable star V838 Monocerotis (V838 Mon), located 20,000 light-years away on the periphery of our Galaxy. In early 2002, V838 Mon increased in brightness temporarily to become 600,000 times brighter than our Sun. The reason for the eruption is still unclear.
Hubble has been observing the V838 Mon light echo since 2002. Each new observation of the light echo reveals a new and unique "thin-section" through the interstellar dust around the star. The new images of the light echo were taken with Hubble's Advanced Camera for Surveys in November 2005 (left) and September 2006 (right). Particularly noticeable in the images are numerous whorls and eddies in the interstellar dust, which are possibly produced by effects of magnetic fields.
Credits
NASA, ESA, and H. Bond (STScI)| About The Object | |
|---|---|
| Object Name | V838 Monocerotis, V838 Mon |
| Object Description | Nova-like variable star and surrounding light echo |
| R.A. Position | 07h 4m 4.99s |
| Dec. Position | -3° 50' 50.0" |
| Constellation | Monoceros |
| Distance | The star is ~20,000 light-years (~6 kiloparsecs) away. |
| Dimensions | 2.5 arcminutes (14 light-years or 4.5 parsecs) wide |
| About The Data | |
| Data Description | This image was created from HST data from the following proposals: and : H. Bond (STScI), R. Wagner (University of Arizona), R. White (STScI), R. Corradi (Observatorio del Roque de los Muchachos), L. Crause (University of Cape Town), M. Dopita (Australian National University), A. Henden (United States Naval Observatory), Z. Levay (STScI), U. Munari (Universita di Padova), N. Panagia (STScI/ESA), W. Sparks (STScI), S. Starrfield (Arizona State University), and B. Sugerman (STScI). |
| Instrument | HST>ACS/WFC |
| Exposure Dates | November 17, 2005 (left) and September 9, 2006 (right) |
| Filters | F606W (V) and F814W (I) |
| About The Image | |
| Color Info | This image is a composite of many separate exposures made by the ACS instrument on the Hubble Space Telescope. Two filters were used to sample broad wavelength ranges. The color results from assigning different hues (colors) to each monochromatic image. In this case, the assigned colors are: Blue: F606W (V) Greed: F606W (V) + F814W (I) Red: F814W (I) |
| About The Object | |
|---|---|
| Object Name | A name or catalog number that astronomers use to identify an astronomical object. |
| Object Description | The type of astronomical object. |
| R.A. Position | Right ascension – analogous to longitude – is one component of an object's position. |
| Dec. Position | Declination – analogous to latitude – is one component of an object's position. |
| Constellation | One of 88 recognized regions of the celestial sphere in which the object appears. |
| Distance | The physical distance from Earth to the astronomical object. Distances within our solar system are usually measured in Astronomical Units (AU). Distances between stars are usually measured in light-years. Interstellar distances can also be measured in parsecs. |
| Dimensions | The physical size of the object or the apparent angle it subtends on the sky. |
| About The Data | |
| Data Description |
|
| Instrument | The science instrument used to produce the data. |
| Exposure Dates | The date(s) that the telescope made its observations and the total exposure time. |
| Filters | The camera filters that were used in the science observations. |
| About The Image | |
| Image Credit | The primary individuals and institutions responsible for the content. |
| Publication Date | The date and time the release content became public. |
| Color Info | A brief description of the methods used to convert telescope data into the color image being presented. |
| Orientation | The rotation of the image on the sky with respect to the north pole of the celestial sphere. |
